Paraquat induces apoptosis, programmed necrosis, and immune dysfunction in CIK cells via the PTEN/PI3K/AKT axis

Protective effects of Silibinin and cinnamic acid against paraquat-induced lung toxicity in rats: impact on oxidative stress, PI3K/AKT pathway, and miR-193a signaling

Levels of reactive oxygen species (ROS) are the primary determinants of pulmonary fibrosis. It was discovered that antioxidants can ameliorate pulmonary fibrosis caused by prolonged paraquat (PQ) exposure. However, research on the precise mechanisms by which antioxidants influence the signaling pathways implicated in pulmonary fibrosis induced by paraquat is still insufficient. This research utilized a rat model of pulmonary fibrosis induced by PQ to examine the impacts of Silibinin (Sil) and cinnamic acid (CA) on pulmonary fibrosis, with a specific focus on pro-fibrotic signaling pathways and ROS-related autophagy. Lung injury induced by paraquat was demonstrated to be associated with oxidative stress and inflammation of the lungs, downregulated (miR-193a), and upregulated PI3K/AKT/mTOR signaling lung tissues. Expression levels of miR-193a were determined with quantitative real-time PCR, protein level of protein kinase B (Akt), and phosphoinositide 3-Kinase (PI3K) which were determined by western blot analysis. Hydroxyproline levels (HYP) and transforming growth factor-β1 (TGF-β1) were measured by ELISA, malondialdehyde (MDA), total antioxidant capacity (TAC), glutathione peroxidase (GSH), and catalase and were measured in lung tissue homogenates colorimetrically using spectrophotometer. Long-term exposure to paraquat resulted in decreased PI3K/AKT signaling, decreased cell autophagy, increased oxidative stress, and increased pulmonary fibrosis formation. Silibinin and cinnamic acid also decreased oxidative stress by increasing autophagy and miR-193a expression, which in turn decreased pulmonary fibrosis. These effects were associated by low TGF-β1. Silibinin and cinnamic acid inhibited PQ-induced PI3K/AKT by stimulating miR-193-a expression, thus attenuating PQ-induced pulmonary fibrosis.

Oxidative toxicity mediated oophoritis alters ovarian growth in Channa punctatus under prolonged exposure to herbicide, paraquat dichloride

Herbicide paraquat dichloride, a potent redox agent found its way to natural water bodies and influences their health; however, its impact on the reproductive health of fish is potentially less studied and requires clear investigation. This study was conducted to elucidate its effect on the gonadal health of female fish, Channa punctatus over 60 days. The 96-h LC50 of test herbicide was calculated as 0.24 mL/L for the fish under examination, subsequently, three sub-lethal concentrations were taken in addition to control for the study. The experimental methodology included assessment of oxidative stress markers, hormone levels, expression of interrelated genes, and histological analysis to ascertain the damage to the ovary. At each exposure period, a significant (p < 0.05) rise in endogenous reactive oxygen species in blood cells and activities of oxidative markers in the ovary tissue were observed in treated groups. The gonadosomatic index of the ovary and hormone concentration in plasma decreased at the highest treatment concentration. A significant (p < 0.05) change in the expression of target genes for ovary growth, inflammation, and apoptosis was observed in the treated fish. Histopathological and ultrastructural investigations of the ovary tissue revealed the occurrence of oophoritis and reduced growth of the ovary in herbicide-treated fish. The findings conclude that, herbicide paraquat dichloride causes inflammation in the ovary, in addition to its growth reduction that ultimately, poses a threat to the fish population.

Effects of Bacillus coagulans on kidney injury caused by Klebsiella pneumoniae in rabbits

Klebsiella pneumoniae (KP) is a zoonotic conditionally pathogenic bacterium with a high prevalence of infection. It often induces purulent inflammation of the rabbit lungs, kidneys and other tissues, with high morbidity and mortality. Bacillus coagulans (BC) has the ability to regulate the balance of host intestinal flora and improve host immunity. However, the mechanism of the protective effect of BC on KP-induced kidney injury in rabbits is not clear. To explore this, we randomly divided fifty 35-day-old Eyplus rabbits into five groups: control, KP, low-dose BC (LBC), medium-dose BC (MBC) and high-dose BC (HBC). On the 1st day of the experiment, rabbits in LBC, MBC and HBC groups were fed diets containing 1 × 106 CFU/g, 5 × 106 CFU/g and 1 × 107 CFU/g BC, respectively, and rabbits in CK and KP groups were fed basal diets. On the 8th day, each rabbit in the KP, LBC, MBC and HBC groups was infused with 4 mL of 1 × 1011 CFU/mL KP bacterial solution, and the CK group was infused with the same amount of sterilised saline for a total of 7 days. Rabbit kidney tissues were collected on the 15th d. HE staining was used to observe the pathological changes of rabbit kidney tissues, oxidative stress-related indexes were detected by biochemical kits, and the content of inflammatory factors and apoptosis-related factors in kidney tissues were detected by ELISA. The results showed that KP disrupts the normal structure of the kidney, induces oxidative stress and inflammatory responses, and mediates apoptosis by regulating the levels of Bcl-2 family proteins. BC pretreatment significantly reduced kidney structural damage, oxidative stress, inflammatory response, and apoptosis in rabbits. To alleviate KP-induced kidney injury by increasing the activity of antioxidant enzymes and the content of anti-apoptotic proteins. Compared with the LBC group and the HBC group, the remission effect was more pronounced in the MBC group. Therefore, in this study, the effect of 5 × 106 CFU/g BC was more significant.

Resveratrol alleviates Mono-2-ethylhexyl phthalate-induced mitophagy, ferroptosis, and immunological dysfunction in grass carp hepatocytes by regulating the Nrf2 pathway

Mono-2-ethylhexyl phthalate (MEHP) is the major biologically active metabolite of Di(2-ethylhexyl) phthalate (DEHP). This MEHP mono-ester metabolite can be transported through the bloodstream into tissues such as the liver, kidneys, fat, and testes and cause corresponding damage. Resveratrol (RSV) has anti-inflammatory, antioxidant, and detoxification characteristics. Our research examined whether RSV alleviates MEHP-induced grass carp hepatocyte (L8824 cell) injury and its relationship with the Nrf2 pathway, mitophagy, ferroptosis, and immune function. Therefore, we treated L8824 cells with 85 μM MEHP and/or 2 μM RSV. The findings indicated that exposing MEHP resulted in increased reactive oxygen species (ROS) content and decreased mitochondrial membrane potential in L8824 cells, which induced an up-regulation of the expression of mitophagy-related indicators (PINK1, Parkin, Beclin1, LC3B, and ATG5) and a down-regulation of P62. An up-regulation of the expression of the ferroptosis-related indicators TFR1 and COX-2, and GPX4 and FTH expression was down-regulated. In addition, there was a decrease in the expression of IL-2 and IFN-γ and an increase in the expression of inflammatory cytokines such as TNF-α, IL-1β, and IL-6 after exposure to MEHP. RSV activates the Nrf2 pathway and effectively alleviates MEHP-induced mitophagy, ferroptosis, and immunologic dysfunction of L8824 cells.

Paraquat-Induced Toxicities: Epidemiological Insights and Advances in Colorimetric and Fluorimetric Detection Methods

Paraquat (PQ) is a potent and widely utilized herbicide known for its effectiveness in controlling a broad spectrum of weeds. Its chemical properties make it an invaluable tool in agriculture, where it helps maintain crop yields and manage invasive plant species. However, despite its benefits in weed management, PQ poses significant risks due to its severe toxicity, which affects multiple organ systems in both humans and animals. The dual nature of PQ, as both a valuable agricultural chemical and a hazardous toxicant, necessitates a comprehensive understanding of its toxicological impacts and the development of effective detection and development strategies. This review aims to provide a comprehensive overview of PQ-induced toxicities, including neurotoxicity, lung toxicity, liver toxicity, kidney toxicity, and immunotoxicity. By synthesizing current knowledge on PQ health impacts, highlighting epidemiological trends, and exploring recent advancements in colorimetric and fluorimetric detection methods, this review seeks to contribute to the development of strategies for improving public health outcomes and enhancing our ability to manage the risks associated with PQ exposure. Addressing PQ toxicity through a multidisciplinary approach, incorporating toxicological, epidemiological, and technological perspectives, is essential for safeguarding health and promoting effective interventions.

Herbicide paraquat dichloride augments the expression of the c-abl-noxa-apoptotic pathway, instigating ovarian atresia in edible fish, Channa punctatus

Ovarian cells of animals undergo atresia to regulate egg numbers and their release. However, unrestrained atretic activity decreases the chances of oocyte maturity and further process, ultimately resulting in a reduced population. Edible fishes are a critical source of nutrition and it is required to regulate their population. The application of herbicides at fish production sites is a threat to their population by altering female reproductive activity. In concern to this, here, this 60-day study investigates herbicide paraquat dichloride (PD)-induced atresia in ovarian cells of Channa punctatus (C. punctatus). Further, 96-h LC50 of PD for C. punctatus was calculated as 58.40 mg/L. At the end of each exposure period, an increase in intracellular ROS in blood cells and activities of SOD and CAT in ovary tissue were observed in PD-treated fish with increasing concentration. The frequency of micronuclei in blood cells subsequently increased with the highest PD concentration. A significant (p < 0.05) increase in the relative expression of target genes was observed at the 30th and 60th day of the sampling periods in the fish treated with the highest concentration of PD. The histological study confirmed the occurrence of atretic ovary cells in PD-exposed fish. From the results it can be concluded that PD enhances the uncontrolled death of ovarian cells and has consequences of impairing the ovary health and reproductive potential of fish, hence reducing the fish population.

Paraquat disrupts the blood-brain barrier by increasing IL-6 expression and oxidative stress through the activation of PI3K/AKT signaling pathway

Background

Paraquat (PQ) is a frequently used herbicide with neurotoxic effects after acute or chronic exposure. Although in vitro evidence supports the PQ toxicity to dopamine cells, its in vivo effects (especially the chronic exposure) remain ambiguous. In this study, we investigated the effect of chronic PQ exposure on the blood-brain barrier (BBB) damage and the underlying mechanisms.

Methods

Adult male Sprague Dawley rats and primary human brain microvascular endothelial (PHBME) cells were exposed to PQ as the animal and cell models. Evans Blue staining and hematoxylin & eosin staining were conducted to examine the BBB and brain tissue damages. The inflammatory cytokines were quantified via enzyme linked immunosorbent assay. The changes of PI3K/AKT signaling pathway were detected by western blot.

Results

PQ exposure can cause significant pathological lesions in the brain tissues and the BBB. IL-6 and reactive oxygen species levels were found to be significantly upregulated after PQ exposure in both the animal and cell models. PQ treatment could arrest the cell proliferation and migration in PHBME cells. PQ treatment promoted the phosphorylation of PI3K and AKT, and the application of PI3K inhibitor could attenuate PQ-induced IL-6 production, oxidative stress, BBB disruption, and brain tissue damage.

Conclusion

Our study demonstrated that chronic PQ exposure could impair the BBB function and induce brain tissue damage. The overactivation of the PI3K/AKT pathway, consequent upregulation of IL-6 production, and increased oxidative stress appear to mediate the inflammatory damage resulting from PQ exposure.

The interactive effect of seven weeks aerobic exercise training and piperine against paraquat-induced lung damage in male Wistar rats: Investigating role of oxidative and inflammatory indices

We aimed to evaluate the effects of seven weeks of aerobic exercise training and piperine on paraquat-induced lung damage. Forty-eight male Wistar rats (230 g, six-eight weeks old) were randomly divided into six groups (n = 8): sham, paraquat (5 mg/kg three times a week; intraperitoneally), paraquat + piperine (10 mg/kg/day; orally), paraquat + aerobic exercise training, paraquat + piperine + aerobic exercise training; and paraquat + vitamin E (20 mg/kg/day; orally) as a positive control. Rats were sacrificed on day 50, and both lung tissues were isolated to measure oxidative (MDA), anti-oxidative (GSH), inflammatory (TNF-α), anti-inflammatory (IL-10) markers, and histological evaluations (hematoxylin-eosin staining). The results of the present study revealed that paraquat significantly decreased body weight, GSH, GSH/MDA ratio, IL-10, and IL-10/TNF-α ratio while increasing MDA, TNF-α, and histopathological damage in lung tissue (P < 0.01 to 0.001). In contrast, treatment with all four interventions meaningfully diminished oxidative, inflammatory markers, and histopathological damage while propagating body weight, anti-oxidative and anti-inflammatory markers following the paraquat-induced lung damage (P < 0.05 to P < 0.001). Interestingly, piperine and piperine + exercise training possessed stronger protective effects against paraquat-induced lung damage than exercise training alone (P < 0.01 to 0.001). Treatment with piperine, exercise training, piperine + exercise training, and vitamin E significantly ameliorated paraquat-induced lung damage. Interestingly, the piperine and piperine + exercise training had more protective effects than other groups. Therefore, piperine and the combination of piperine and exercise training may be valuable candidates for preventing lung injuries.

Ferulic acid alleviates avermectin induced renal injury in carp by inhibiting inflammation, oxidative stress and apoptosis

Avamectin (AVM), a macrolide antibiotic, is widely used in fisheries, agriculture, and animal husbandry, however, its irrational use poses a great danger to aquatic organisms. Ferulic acid (FA) is a natural chemical found in the cell walls of plants. It absorbs free radicals from the surrounding environment and acts as an antioxidant. However, the protective effect of FA against kidney injury caused by AVM has not been demonstrated. In this study, 60 carp were divided into the control group, AVM group (2.404 μg/L), FA+AVM group and FA group (400 mg/kg). Pathological examination, quantitative real-time PCR (qPCR), reactive oxygen species (ROS) and western blot were used to evaluate the preventive effect of FA on renal tissue injury after AVM exposure. Histological findings indicated that FA significantly reduced the swelling and infiltration of inflammatory cells in the kidney tissues of carp triggered by AVM. Dihydroethidium (DHE) fluorescent probe assay showed that FA inhibited the accumulation of kidney ROS. Biochemical results showed that FA significantly increased glutathione (GSH) content, total antioxidant capacity (T-AOC) and catalase (CAT) activity, and decreased intracellular malondialdehyde (MDA) content. In addition, western blot results revealed that the protein expression levels of Nrf2 and p-NF-κBp65 in the carp kidney were inhibited by AVM, but reversed by the FA. The qPCR results exhibited that FA significantly increased the mRNA levels of tgf-β1 and il-10, while significantly down-regulated the gene expression levels of tnf-α, il-6 and il-1β. These data suggest that FA can reduce oxidative stress and renal tissue inflammation induced by AVM. At the same time, FA inhibited the apoptosis of renal cells induced by AVM by decreasing the transcription level and protein expression level of Bax, and increasing the transcription level and protein expression level of Bcl2, PI3K and AKT. This study provides preliminary evidence for the theory that FA reduces the level of oxidative stress, inflammation response and kidney tissue damage caused by apoptosis in carp, providing a theoretical basis for the prevention and treatment of the AVM.

TAN (tannic acid) inhibits BPA-induced pyroptosis of L8824 (grass carp hepatocytes) by regulating PTEN/PI3K/AKT pathway

Bisphenol A (BPA) and its analogues are still one of the most important substances that pollute aquatic systems and pose a threat to aquatic organisms. Tannic acid (TAN) is a kind of glycosyl compound, which has the functions of anti-oxidation, anti-inflammation and anti-apoptosis. However, it is unknown if BPA can regulate PTEN/PI3K/AKT pathway to induce pyroptosis of grass carp hepatocytes (L8824) and the antagonistic effect of tannic acid (TAN) through oxidative stress. Therefore, we established the grass carp hepatocytes (L8824) cell model treated with BPA. The oxidative stress indexes (SOD, CAT, GSH, H2O2 and T-AOC) were detected by oxidative stress kit, mRNA and protein expression of associated genes were examined using qRT-PCR and western blotting. The results showed that BPA treatment increased the content of hydrogen peroxide and decreased the activities of antioxidant enzymes and antioxidants (SOD, CAT, GSH, and T-AOC) in L8824 cells. We also found that PTEN/PI3K/AKT pathway was activated dramatically and the expression of pyroptosis-related genes (GSDMD, NLRP3, Caspase1, ASC and IL-1β) was increased significantly. In addition, TAN could significantly reduce the toxicity of BPA on L8824 cells. After the addition of PTEN specific inhibitor SF1670, the activation of PTEN/PI3K/AKT pathway decreased by BPA was inhibited and the expression of scorch related genes was decreased. On the whole, TAN inhibits BPA-induced pyroptosis of L8824 by modulating the PTEN/PI3K/AKT pathway. The present study provides a novel perspective for toxicological mechanism of BPA, and new insights into the detoxification mechanism of TAN.

1,2-bis(2,4,6-tribromophenoxy) ethane, a novel brominated flame retardant, disrupts intestinal barrier function via the IRX3/NOS2 axis in rat small intestine

Novel brominated flame retardants are widely used in electronics, textiles, furniture, and other products; they can enter the human body through ingestion and respiration and cause harm to the human body, and have been proven to have potential biological toxicity and accumulation effects. 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE) is a widely used novel brominated flame retardant; however, there is a lack of research on its mechanism of toxicity, particularly that of intestinal toxicity. Currently, studies on the functionality of iroquois homeobox 3 (IRX3) are extremely limited. In our study, BTBPE was administered to Sprague-Dawley (SD) rats and rat small intestinal crypt epithelial cells (IEC6 cells) in vivo and in vitro, respectively, and hematoxylin and eosin (HE), immunohistochemical, Alcian blue-periodic acid-Schiff (AB-PAS), CCK8, acridine orange/ethidium bromide (AO/EB), fluorescent probes, qPCR, western blotting, and immunofluorescence analyses were performed. To explore the damage mechanism of BTBPE, we used siRNA to silence IRX3 and iNOs-IN-1 (yeast extract-peptone-wheat; YPW) to inhibit nitric oxide synthase 2 (NOS2). The results showed that BTBPE exposure caused inflammation and necroptosis in the jejunum and ileum, as well as destruction of the tight junctions and mucus layer. Moreover, BTBPE activated the IRX3/NOS2 axis both in vivo and in vitro. Silencing IRX3 or inhibiting NOS2 inhibits necroptosis and restores tight junctions in IEC6 cells. In conclusion, our study found that in the jejunum, ileum, and IEC6 cells, BTBPE exposure caused necroptosis and tight junction destruction by activating the IRX3/NOS2 axis. Blocking the IRX3/NOS2 axis can effectively inhibit necroptosis and restore tight junction. In addition, BTBPE exposure caused inflammation and loss of the mucous layer in the jejunum and ileum. Our study is the first to explore the mechanism of intestinal damage caused by BTBPE exposure and to discover new biological functions regulated by the IRX3/NOS2 axis, providing new research directions for necroptosis and tight junctions.

A study on the effectiveness of sodium selenite in treating cadmium and perfluoro octane sulfonic (PFOS) poisoned zebrafish (Danio rerio)

Perfluoro octane sulfonate (PFOS) and cadmium (Cd) are toxic elements in the environment. As a micronutrient trace element, selenium (Se) can mitigate the adverse effects induced by PFOS and Cd. However, few studies have examined the correlation between Se, PFOS and Cd in fish. The present study focused on the antagonistic effects of Se on PFOS+Cd-induced accumulation in the liver of zebrafish. The fish was exposed to PFOS (0.08mg/L), Cd (1mg/L), PFOS+ Cd (0.08 mg/L PFOS+1 mg/L Cd), L-Se (0.07mg/L Sodium selenite +0.08mg/L PFOS+1mg/L Cd), M-Se (0.35mg/L Sodium selenite + 0.08mg/L PFOS+ 1 mg/L Cd), H-Se (1.75 mg/L Sodium selenite + 0.08 mg/L PFOS+ 1mg/L Cd) for 14d. The addition of selenium to fish exposed to PFOS and Cd has been found to have significant positive effects. Specifically, selenium treatments can alleviate the adverse effects of PFOS and Cd on fish growth, with a 23.10% improvement observed with the addition of T6 compared to T4. In addition, selenium can alleviate the negative effects of PFOS and Cd on antioxidant enzymes in zebrafish liver, thus reducing the liver toxicity caused by PFOS and Cd. Overall, the supplementation of selenium can reduce the health risks to fish and mitigate the injuries caused by PFOS and Cd in zebrafish.

Ferulic acid alleviates carp brain damage and growth inhibition caused by avermectin by modulating the Nrf2/Keap1 and NF-κB signaling pathways

The increasing concern over environmental pollution caused by the pesticide avermectin used in aquaculture has attracted significant attention. The use of avermectin, a neurotoxic pesticide, in aquatic environments leads to toxic effects on non-target organisms, particularly causing harm to fish. The phenolic compound ferulic acid possesses excellent anti-inflammatory and antioxidant capabilities. This study was conducted by establishing a chronic exposure experiment to avermectin, proposes the use of ferulic acid as a dietary additive to protect the carp brain from damage caused by exposure to avermectin. Furthermore, it investigates the anti-inflammatory and antioxidant effects of ferulic acid in the carp brain under chronic exposure to avermectin. The experimental results demonstrate that ferulic acid can alleviate brain tissue inflammation and oxidative stress by modulating the Nrf2/Keap1 and NF-κB signaling pathways. It protects the carp brain from chronic avermectin-induced damage, preserves the integrity of the carp blood-brain barrier, enhances the levels of feeding factors, and thereby alleviates carp growth inhibition. These findings provide new therapeutic strategies and a theoretical foundation for the sustainable development of carp aquaculture.

Selenium deficiency caused hepatitis in chickens via the miR-138-5p/SelM/ROS/Ca2+ overload pathway induced by hepatocyte necroptosis

Selenoprotein M (SelM), a key thioredoxin like enzyme in the endoplasmic reticulum (ER), is closely related to hepatocyte degeneration. However, the role of miR-138-5p/SelM and necroptosis in chicken SelM-deficient hepatitis and the specific biological mechanism of liver inflammation caused by SelM deficiency have not been elucidated. We established an in vivo chicken liver Se deficiency model by feeding a low-Se diet. The miR-138-5p knockdown and overexpression models and SelM knockdown models were established in LMH cells for an in vitro study. Transmission electron microscopy, H&E staining, Fluo4-AM/ER staining, and flow cytometry were used to detect the morphological changes in chicken liver tissue and the expression changes of necroptosis and inflammation in chicken liver cells. We observed that Se deficiency resulted in liver inflammation, up-regulation of miR-138-5p expression and down-regulation of SelM expression in chickens. Oxidative stress, Ca2+ overload, energy metabolism disorder and necroptosis occurred in chicken liver tissue. Importantly, ROS and the Ca2+ inhibitor could effectively alleviate the energy metabolism disorder, necroptosis and inflammatory cytokine secretion caused by miR-138-5p overexpression and SelM knockdown in LMH cells. In conclusion, selenium deficiency causes hepatitis by upregulating miR-138-5p targeting SelM. Our research findings enrich our knowledge about the biological functions of SelM and provide a theoretical basis for the lack of SelM leading to liver inflammation in chickens.

Phenylalanine Plays Important Roles in Regulating the Capacity of Intestinal Immunity, Antioxidants and Apoptosis in Largemouth Bass (Micropterus salmoides)

This experiment was planned to explore the role of dietary phenylalanine levels in intestinal immunity, antioxidant activity and apoptosis in largemouth bass (Micropterus salmoides). Six iso-nitrogen and iso-energy diets with phenylalanine levels of 1.45% (DPHE1), 1.69% (DPHE2), 1.98% (DPHE3), 2.21% (DPHE4), 2.48% (DPHE5) and 2.76% (DPHE6) were designed. Juvenile largemouth bass were fed the experimental diet for 8 weeks. In this study, the DPHE5 group increased the expression of intestinal antioxidant genes in largemouth bass (p < 0.05), and the increase of antioxidant enzyme activities and content of related substances was most concentrated in the DPHE3 and DPHE4 groups (p < 0.05). The results of plasma biochemistry were similar to that of enzyme activity. The expression of genes related to the TOR signalling pathway mainly increased significantly in the DPHE5 group (p < 0.05). Similarly, the expression of inflammatory factors, as well as apoptotic factors, also showed significant increases in the DPHE5 group (p < 0.05). In conclusion, unbalanced phenylalanine in the diet could lead to a decrease in intestinal immune and antioxidant capacity and also cause a decline in the aggravation of intestinal cell apoptosis.

Molecular mechanism of kidney damage caused by abamectin in carp: Oxidative stress, inflammation, mitochondrial damage, and apoptosis

Indiscriminate use of pesticides not only leads to environmental pollution problems, but also causes poisoning of non-target organisms. Abamectin (ABM), a widely used insecticide worldwide, is of wide concern due to its persistence in the environment and its high toxicity to fish. The kidney, as a key organ for detoxification, is more susceptible to the effects of ABM. Unfortunately, few studies investigated the mechanisms behind this connection. In this study, carp was used as an indicator organism for toxicological studies to investigate renal damage caused by ABM residues in carp. In this work, carp were exposed to ABM (0, 3.005, and 12.02 μg/L) for 4 d and the nephrotoxicity was assessed. Histopathological findings revealed that ABM exposure induced kidney damage in carp, as well as an increase Creatinine and BUN levels. Meanwhile, ABM as a reactive oxygen species (ROS) stimulator, boosted ROS bursts and lowered antioxidant enzyme activity while activating the body's antioxidant system, the Nrf2-Keap1 signaling pathway. The accumulation of ROS can also lead to the imbalance of the body's oxidation system, leading to oxidative stress. At the same time, NF-κB signaling pathway associated with inflammation was activated, which regulated expression levels of inflammatory cytokines (TNF-α, IL-6, IL-1β, and iNOS increased, while IL-10 and TGF-β1 decreased). In addition, ABM exposure caused structural damage to kidney mitochondria of carp, resulting in decreased mitochondrial membrane potential and ATP production capacity, and mediated apoptosis through endogenous pathways Bax/Bcl-2/Caspase-9/Caspase-3. In conclusion, ABM caused kidney damage in carp by inducing oxidative stress, inflammation, and apoptosis through mitochondrial pathway. These findings will be useful for future research into molecular mechanisms of ABM-induced nephrotoxicity in aquatic organisms.

Di (2-ethyl) hexyl phthalate induces liver injury in chickens by regulating PTEN/PI3K/AKT signaling pathway via reactive oxygen species

Di (2-ethyl) hexyl phthalate (DEHP) is a common environmental endocrine disruptor that induces oxidative stress, posing a significant threat to human and animal health. Oxidative stress can activate the PTEN/PI3K/AKT pathway, which is closely related to cell apoptosis. However, it is unclear whether DEHP induces apoptosis of chicken liver cells by regulating the PTEN/PI3K/AKT pathway through oxidative stress. In this experiment, male laying hens were continuously exposed to 400 mg/kg, 800 mg/kg, and 1600 mg/kg DEHP for 14 d, 28 d, and 42 d. The results showed that liver injury was aggravated with the dose of DEHP gavage, and the ROS/MDA levels in L, M, and H DEHP exposure groups were significantly increased, while the T-AOC/T-SOD/GSH-PX levels were decreased. Meanwhile, DEHP exposure up-regulated the mRNA and protein expression levels of PTEN/Bax/Caspase-9/Caspase-3 and down-regulated the mRNA and protein expression levels of PI3K/AKT/BCL-2, indicating that DEHP may lead to hepatocyte apoptosis through ROS regulation of PTEN/PI3K/AKT axis. In order to further clarify the relationship between oxidative stress and liver injury, we treated chicken hepatocellular carcinoma cell line (LMH) with 2.5 mM N-acetylcysteine (NAC). NAC attenuated these phenomena. In summary, our study suggests that DEHP can induce apoptosis of chicken liver through ROS activation of the PTEN/PI3K/AKT axis.

Ozone-oxidized black carbon particles change macrophage fate: Crosstalk between necroptosis and macrophage extracellular traps

The impacts of environmental PM 2.5 on public health have become a major concern all over the world. Many studies have shown that PM 2.5 still poses a threat to public health even at very low levels. Physical or chemical reactions occur between primary particles and other components in the environment, which changes the properties of primary particles. Such newly formed particles with changed properties are called secondary particles. Ozone-oxidized black carbon (oBC) is a key part of PM 2.5 and a representative secondary particle. Macrophages extracellular traps (METs) is a means for macrophages to capture and destroy invading pathogens, thereby exercising innate immunity. Necroptosis is a kind of programmed cell death, which is accompanied by the destruction of membrane integrity, thus inducing inflammatory reaction. However, there is no research on the crosstalk mechanism between necroptosis and MET after oBC exposure. In our study, AO/EB staining, SYTOX Green staining, fluorescent probe, qPCR, Western blot, and immunofluorescence were applied. This experiment found that under normal physiological conditions, when macrophages receive external stimuli (such as pathogens; in our experiment: phorbol 12-myristate 13-acetate (PMA)), they will form METs, capture and kill pathogens, thus exerting innate immune function. However, exposure to oBC can cause necroptosis in macrophages, accompanied by increased levels of reactive oxygen species (ROS) and cytosolic calcium ions, as well as the expression disorder of inflammatory factors and chemokines, and prevent the formation of METs, lose the function of capturing and killing pathogens, and weaken the innate immune function. Notably, inhibition of necroptosis restored the formation of METs, indicating that necroptosis inhibited the formation of METs. This study was the first to explore the crosstalk mechanism between necroptosis and METs after oBC exposure.

Perfluorooctane sulfonate-induced apoptosis in kidney cells by triggering the NOX4/ROS/JNK axis and antagonism of cannabidiol

Perfluorooctane sulfonate (PFOS) is one of the persistent organic pollutants (POPs), which can cause severe nephrotoxicity in mammals. Cannabinol (CBD), a nonpsychoactive cannabinoid obtained from the cannabis plant, has attracted attention in recent years for its excellent antioxidant properties. NADPH oxidase 4 (NOX4) has an important effect in supporting normal renal physiological function. The potential mechanisms of PFOS nephrotoxicity and whether CBD can prevent renal damage caused by PFOS remain unclear. This work aimed to study the mechanisms of PFOS-induced kidney damage and the protective role of CBD against PFOS-induced kidney damage. We demonstrated that PFOS led to renal insufficiency and structural damage in mice, induced overexpression of NOX4 and the onset of oxidative stress, and activated apoptosis of the mitochondrial pathway via the JNK signaling pathway. However, treatment with CBD reversed these changes. For further investigation of the potential mechanism of PFOS-induced renal cell apoptosis, the expression of NOX4 was inhibited in vitro experiments using Apocynin, an effective NOX4 inhibitor. The outcomes showed that PFOS-induced ROS production and JNK signaling pathway activation and apoptosis in human embryonic kidney (HEK293) cells were significantly reduced after inhibition of NOX4. This suggests that PFOS-induced NOX4 overexpression serves as an upstream event for JNK pathway activation. In conclusion, the findings suggest that PFOS induces apoptosis in renal cells via the NOX4/ROS/JNK pathway. Meanwhile, CBD alleviated PFOS-induced renal apoptosis through the inhibition of NOX4/ROS/JNK axis activation.

Effect of Europinidin against Alcohol-Induced Liver Damage in Rats by Inhibiting the TNF-α/TGF-β/IFN-γ/NF-kB/Caspase-3 Signaling Pathway

BACKGROUND

The effect of europinidin on alcoholic liver damage in rats was examined in this research.

METHODS

A total of 24 Wistar rats were grouped in the same way into four groups: normal control (normal), ethanol control (EtOH), europinidin low dose (10 mg/kg), and europinidin higher dose (20 mg/kg). The test group rats were orally treated with europinidin-10 and europinidin-20 for 4 weeks, whereas 5 mL/kg distilled water was administered to control rats. In addition, 1 h after the last dose of the above-mentioned oral treatment, 5 mL/kg (i.p.) EtOH was injected to induce liver injury. After 5 h of EtOH treatment, samples of blood were withdrawn for biochemical estimations.

RESULTS

Administration of europinidin at both doses restored all of the estimated serum, i.e., liver function tests (ALT, AST, ALP), biochemical test (Creatinine, albumin, BUN, direct bilirubin, and LDH), lipid assessment (TC and TG), endogenous antioxidants (GSH-Px, SOD, and CAT), malondialdehyde (MDA), nitric oxide (NO), cytokines (TGF-β, TNF-α, IL-1β, IL-6, IFN-γ, and IL-12), caspase-3, and nuclear factor kappa B (NF-κB) associated with the EtOH group.

CONCLUSION

The results of the investigation showed that europinidin had favorable effects in rats given EtOH and may have hepatoprotective potential property.

Black carbon nanoparticles activate the crosstalk mechanism between necroptosis and macrophage extracellular traps to change macrophages fate

PM2.5 still poses a threat to public health even at very low levels. Black carbon (BC) is a key component of PM2.5. Macrophage extracellular traps (METs) are a means by which macrophages capture and destroy invading pathogens. Necroptosis is an inflammatory programmed cell death. However, there is no research on the crosstalk mechanism between necroptosis and METs after BC exposure. In our study, fluorescence labeling, fluorescent probes, qPCR, and immunofluorescence were applied. Our research found that under normal physiological conditions, when macrophages receive external stimuli (in our experiment, phorbol 12-myristate 13-acetate (PMA)), they will form METs, thus exhibiting innate immune function. However, exposure to BC can cause necroptosis in macrophages accompanied by increased levels of ROS and cytosolic calcium ions as well as altered expression of inflammatory factors and chemokines that prevent the formation of METs, and weakening innate immune function. Notably, inhibition of necroptosis restored the formation of METs, indicating that necroptosis inhibits the formation of METs. Our experiment will enrich the understanding of the mechanism of macrophage injury caused by BC exposure, provide a new direction for studying harmful atmospheric particle toxicity, and propose new therapeutic insights for diseases caused by atmospheric particulate matter. This study is the first to explore the crosstalk mechanism between necroptosis and METs after BC exposure.

Protective effect of quercetin on avermectin induced splenic toxicity in carp: Resistance to inflammatory response and oxidative damage

Avermectin pollution is an important problem that cannot be ignored in aquatic system in recent years. It has brought great trouble to freshwater aquaculture, especially fishery aquaculture. Plant-derived quercetin has anti-inflammatory and antioxidant properties and is widely used as a dietary additive, but its protective effect on immune damage induced by avermectin in freshwater carp remains unclear. This study evaluated the role of dietary additive quercetin supplementation in chronic avermectin exposure of carp spleen. Sixty carp were divided into 4 groups (n = 15/ group), including control group, avermectin treatment group, quercetin treatment group, quercetin and avermectin co-treatment group. Carp were exposed to a 1/10 96 h LC₅₀ dose of avermectin for 30 d and fed a carp diet containing 400 mg/kg quercetin twice a day (3% body weigh/ carp). The results showed that chronic avermectin exposure caused the loose parenchymal structure of carp spleen tissue and the increase of inflammatory cells, accompanied by increased transcription levels of pro-inflammatory il-1β, il-6, tnf-α and decreased levels of anti-inflammatory factors il-10 and tgf-β1, ROS accumulation in spleen tissue. MDA content increased and T-AOC, CAT and GSH levels decreased. Quercetin down-regulates the NF-κB pathway by inhibiting the expression of iNOS and activating p38 MAPK, blocking the transcription of inflammatory factors, and alleviating the inflammation of carp spleen caused by chronic avermectin exposure. In addition, quercetin inhibits the over-activation of Nrf2/Keap-1 signaling axis, blocks ROS accumulation, and restores the spleen REDOX homeostasis. In conclusion, quercetin, as a dietary additive for carp feed, can effectively improve the immune damage caused by avermectin pollution in aquatic environment, resist spleen inflammation and oxidative stress, and provide a theoretical basis for clinical development of freshwater carp feed.

Glyphosate induces autophagy in hepatic L8824 cell line through NO-mediated activation of RAS/RAF/MEK/ERK signaling pathway and energy metabolism disorders

Glyphosate is an herbicide commonly used worldwide, and its substantial use causes widespread pollution with runoff. However, research on glyphosate toxicity has mostly remained at the embryonic level and existing studies are limited. In the present study, we investigated whether glyphosate can induce autophagy in hepatic L8824 cells by regulating energy metabolism and rat sarcoma (RAS)/rapidly accelerated fibrosarcoma (RAF)/mitogen-activated extracellular signal-regulated kinase (MEK)/extracellular regulated protein kinases (ERK) signaling by activating nitric oxide (NO). First, we selected 0, 50, 200, and 500 μg/mL as the challenge doses, according to the inhibitory concentration of 50% (IC50) of glyphosate. The results showed that glyphosate exposure increased the enzyme activity of inducible nitric oxide synthase (iNOS), which in turn increased the NO content. The activity and expression of enzymes related to energy metabolism, such as hexokinase (HK)1, HK2, phosphofructokinase (PFK), phosphokinase (PK), succinate dehydrogenase (SDH), and nicotinamide adenine dinucleotide with hydrogen (NADH), were inhibited, and the RAS/RAF/MEK/ERK signaling pathway was activated. This led to the negative expression of mammalian target of rapamycin (mTOR) and P62 in hepatic L8824 cells and the activation of the autophagy marker genes microtubule-associated proteins light chain 3 (LC3) and Beclin1 to induce autophagy. The above results were dependent on glyphosate concentration. To verify whether autophagy can be excited by the RAS/RAF/MEK/ERK signaling pathway, we treated L8824 cells with the ERK inhibitor U0126 and found that the autophagy gene LC3 was reduced due to the inhibition of ERK, thus demonstrating the reliability of the results. In conclusion, our results demonstrate that glyphosate can induce autophagy in hepatic L8824 cells by activating NO, thus regulating energy metabolism and the RAS/RAF/MEK/ERK signaling pathway.

Bisphenol A aggravate selenium deficiency-induced apoptosis via miR-215-3p/Dio1 to activate ROS/PI3K/AKT pathway in chicken arterial

Both bisphenol A (BPA) and selenium (Se) deficiency can affect the expression of microRNAs (miRNAs), which can specifically regulate its target mRNA and induce apoptosis, and play a significant role in cardiovascular injury diseases. To explore the mechanism of apoptosis induced by BPA and Se deficiency in chicken arterial endothelial tissue and the role of miRNAs in this process, the model of BPA exposure/Se deficiency in chicken and PAEC cells have been employed. The targeting relationship between miR-215-3p and iodothyronine deiodinase 1 (Dio1) in PAEC was verified by double luciferase gene report. The level of miR-215-3p was detected by qRT-PCR. The oxidative stress level of arterial endothelial cells was detected by oxidative stress kit and DCFH-DA probe method. The PI3K/AKT pathway, mitochondrial dynamics, and apoptosis-related genes were detected by qRT-PCR and western blot. The mitochondrial ATP level and nitric oxide synthases (NOSs) level were detected with the kit. TUNEL, acridine orange/ethidium bromide, and flow cytometry were used to detect the level of apoptosis. The results showed that BPA exposure and Se deficiency led to overexpression of miR-215-3p, aggravated oxidative stress, inhibited activation of PI3K/AKT pathway, promoted mitochondrial division, increased expression of apoptosis related genes, and finally led to apoptosis of chicken arterial endothelial cells. We also established knockdown/overexpression models of miR-215-3p and Dio1 in vitro, and found that overexpression of miR-215-3p and knockout of Dio1 can induce apoptosis. Interestingly, miR-215-3p-Inhibitor and N-acetyl- l-cysteine (NAC) partially prevented apoptosis caused by BPA exposure and Se deficiency, and LY294002 aggravated apoptosis. These results suggest that BPA exposure aggravates the apoptosis of Se deficient arterial endothelial cells in chickens by regulating the ROS/PI3K/AKT pathway activated by miR-215-3p/Dio1. The miR-215-3p/Dio1 axis provides a new way to understand the toxic mechanism of BPA exposure and Se deficiency, and reveals a new regulatory model of apoptosis damage in vascular diseases.

Di(2-ethylhexyl) phthalate and microplastics cause necroptosis and apoptosis in hepatocytes of mice by inducing oxidative stress

Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer and an endocrine disruptor. Microplastics (MPs) are pathogenic small plastic particles and abundant in the aqueous environment. The problem of residual hazards of plastic products is worthy of study, especially the joint exposure of a variety of plastic-related products to the toxic effect. We used 200 mg/kg DEHP and 10 mg/L MPs to establish exposure model in vivo and 2 mM DEHP and 200 μg/L MPs to establish AML12 cell exposure model in vitro. In vivo study results showed that compared with the control group (NC) group, DEHP and MPs significantly increased the contents of malondialdehyde and hydrogen peroxide, and significantly decreased the contents of glutathione and the activity of superoxide dismutase, total antioxidant capacity, catalase and glutathione peroxidase. The level of oxidative stress was further aggravated after combined exposure. The reactive oxygen species level of AML12 exposed to DEHP and MPs in vitro was significantly higher than NC group, and the combined exposure was significantly higher than the single exposure. The in vivo and in vitro also confirmed that DEHP and MPs could significantly increase the mRNA and protein levels of apoptosis markers and necroptosis markers and there was an additive effect. After N-acetylcysteine treatment in vitro, the above-mentioned oxidative stress level and cell damage decreased significantly. This study provided a reference for advocating the reduction of the mixed use of plastic products, and provided a basis for preventing the harm of plastic products residues.

Cadmium accelerates autophagy of osteocytes by inhibiting the PI3K/AKT/mTOR signaling pathway

Cadmium (Cd) can damage bone cells and cause osteoporosis. Osteocytes are the most numerous bone cells and also important target cells for Cd-induced osteotoxic damage. Autophagy plays important role in the progression of osteoporosis. However, osteocyte autophagy in Cd-induced bone injury is not well characterized. Thus, we established a Cd-induced bone injury model in BALB/c mice and a cellular damage model in MLO-Y4 cells. Aqueous Cd exposure for 16 months showed an increase in plasma alkaline phosphatase (ALP) activity and increase in urine calcium (Ca) and phosphorus (P) concentrations in vivo. Moreover, expression level of autophagy-related microtubule-associated protein 1A/1B-light chain 3 II (LC3II) and autophagy-related 5 (ATG5) proteins were induced, and the expression of sequestosome-1 (p62) was reduced, along with Cd-induced trabecular bone damage. In addition, Cd inhibited the phosphorylation of mammalian target of rapamycin (mTOR), protein kinase B (AKT), and phosphatidylinositol 3-kinase (PI3K). In vitro, 80 μM Cd concentrations exposure upregulated LC3II protein expression, and downregulated of p62 protein expression. Similarly, we found that treatment with 80 μM Cd resulted in a reduction in the phosphorylation levels of mTOR, AKT, and PI3K. Further experiments revealed that addition of rapamycin, an autophagy inducer, enhanced autophagy and alleviated the Cd-induced damage to MLO-Y4 cells. The findings of our study reveal for the first time that Cd causes damage to both bone and osteocytes, as well as induces autophagy in osteocytes and inhibits PI3K/AKT/mTOR signaling, which could be a protective mechanism against Cd-induced bone injury.

Polystyrene-microplastics and DEHP co-exposure induced DNA damage, cell cycle arrest and necroptosis of ovarian granulosa cells in mice by promoting ROS production

The joint pollution of microplastics (MPs) and di-(2-ethylhexyl) phthalic acid (DEHP) often occurs, and consequently poses a serious threat to human and animal health, which has attracted widespread attention. However, the damage to the female mammalian ovary caused by the single exposure and co-exposure of MPs and DEHP and its specific mechanisms are not clear. Here, we established mouse models of single and co-exposures to polystyrene-microplastics (PS-MPs) and DEHP. The results showed that exposed to 100 mg/L PS-MPs and 200 mg/kg DEHP for 35 days destroyed the ovarian granulosa cell layer of mice, leading to follicular fragmentation and atresia. We cultured ovary granulosa cells in vitro to perform further mechanism studies and found that PS-MPs and DEHP had synergistic effects. Both of them promoted the excessive production of ROS and induced oxidative stress by triggering the CNR1/CRBN/YY1/CYP2E1 signaling axis, which in turn caused DNA oxidative damage. Additionally, we provided compelling evidence that oxidative stress mediated-hippo signaling pathway played a critical role in PS-MPs and DEHP caused ovary damage, resulting in ovarian granulosa cell cycle arrest and necroptosis. Using oxidative stress inhibitor AM251 or DAS could reverse these changes markedly and alleviate the reproductive toxicity caused by PS-MPs and DEHP, effectively. Overall, these results demonstrated that co-exposure of PS-MPs and DEHP adversely affected the integrity of ovary granulosa cell layer, resulting in DNA oxidative damage, cell cycle arrest and increased necroptosis of mouse ovarian granulosa cells by inducing oxidative stress. Our study shed new light on the co-exposure toxicity of PS-MPs and DEHP, provided novel insights for the reproductive toxicity of PS-MPs combined exposure with DEHP in female animals from a new free radical generation pathway perspective.

ROS mediated pyroptosis-M1 polarization crosstalk participates in inflammation of chicken liver induced by bisphenol A and selenium deficiency

The earth's natural environmental factors and man-made industrial pollution often lead to the co-occurrence of environmental pathogenic factors and malnutrition. Bisphenol A (BPA) is a serious environmental endocrine disruptor, and its exposure can cause liver tissue damage. Selenium (Se) deficiency is a worldwide problem that afflicts thousands of people, and Se deficiency can cause M1/M2 imbalance. In addition, the crosstalk between hepatocyte and immune cell is closely related to the occurrence of hepatitis. Therefore, this study found for the first time that the combined exposure of BPA and Se deficiency caused liver pyroptosis and M1 polarization through ROS, and the crosstalk between pyroptosis and M1 polarization aggravated liver inflammation in chicken. In this study, the BPA or/and Se deficiency chicken liver, single and co-culture model of LMH and HD11 cells were established. The results displayed that BPA or Se deficiency induced liver inflammation accompanied by pyroptosis and M1 polarization through oxidative stress, and increased expressions of chemokines (CCL4, CCL17, CCL19, and MIF) and inflammatory factors (IL-1β and TNF-α). The vitro experiments further verified the above changes and showed that LMH pyroptosis promoted M1 polarization of HD11 cells, and vice versa. NAC counteracted pyroptosis and M1 polarization caused by BPA and low-Se, reducing the release of inflammatory factors. In brief, BPA and Se deficiency treatment can exacerbate liver inflammation by increasing oxidative stress to induce pyroptosis and M1 polarization.

Low dosage fluorine ameliorates the bioaccumulation, hepatorenal dysfunction and oxidative stress, and gut microbiota perturbation of cadmium in rats

Many "hot spot" geographic areas around the world with soils and crops co-polluted with cadmium (Cd) and fluorine (F), two of the most representative pollutants in the environment. However, it still exists argumentative on the dose-effect relationship between F and Cd so far. To explore this, a rat model was established to evaluate the effects of F on Cd-mediated bioaccumulation, hepatorenal dysfunction and oxidative stress, and the disorder of intestinal microbiota as well. 30 healthy rats were randomly assigned to Control group (C group), Cd 1 mg/kg (Cd group), Cd 1 mg/kg and F 15 mg/kg (L group), Cd 1 mg/kg and F 45 mg/kg (M group), and Cd 1 mg/kg and F 75 mg/kg (H group) for 12 weeks by gavage. Our results showed that Cd exposure could accumulate in organs, cause hepatorenal function damage and oxidative stress, and disorder of gut microflora. However, different dosages of F showed various effects on Cd-induced damages in liver, kidney, and intestine, and only the low supplement of F showed a consistent trend. After low supplement of F, Cd levels were declined by 31.29% for liver, 18.31% for kidney, and 2.89% for colon, respectively. The serum aspartate aminotransferase (AST), blood urea nitrogen (BUN), creatinine (Cr), and N-acetyl-β-glucosaminidase (NAG) were significantly reduced (p < 0.01); The activity of superoxide dismutase (SOD) was elevated and mRNA expression level of NAD(P)H quinone oxidoreductase 1 (NQO1) was decreased in the liver and kidney (p < 0.05). Moreover, low F dosage up-regulated the abundance of Lactobacillus from 15.56% to 28.73% and the 6.23% of F/B ratio was declined to 3.70%. Collectively, this highlights that low dosage of F might be a potential strategy to ameliorate the hazardous effects by Cd-exposed in the environment.

Polystyrene microplastics mediate inflammatory responses in the chicken thymus by Nrf2/NF-κB pathway and trigger autophagy and apoptosis

Microplastics (MPs) are now a hot environmental contaminant. However, researchers paid little attention to their effects on immune organs such as the thymus. Here, we exposed chickens to a concentration gradient of polystyrene microplastics (PS-MPs) and then followed the decrease in the thymus index. HE staining showed cellular infiltration in the thymus. The assay kit corroborated that PS-MPs impelled oxidative stress in the thymus: increased MDA levels, downregulated antioxidants such as SOD, CAT, and GSH, and significantly undermined total antioxidant capacity. Western blotting and qRT-PCR results showed that Nrf2/NF-κB, Bcl-2/Bax, and AKT signaling pathways were activated in the thymus after exposure to PS-MPs. It stimulated the increased expression of downstream such as IL-1β, caspase-3, and Beclin1, triggering thymus inflammation, apoptosis, and autophagy. This study provides new insights into the field of microplastic immunotoxicity and highlights potential environmental hazards in poultry farming.

1,4-Naphthoquinone-Coated Black Carbon, a Kind of Atmospheric Fine Particulate Matter, Affects Macrophage Fate: New Insights into Crosstalk between Necroptosis and Macrophage Extracellular Traps

1,4-Naphthoquinone-coated BC (1,4 NQ-BC) is an important component of PM_2.5 and a representative secondary particle. However, there is no research on the crosstalk mechanism between necroptosis and macrophage extracellular traps (METs) after 1,4 NQ-BC exposure. In this study, we treated RAW264.7 cells with 50, 100, and 200 mg/L 1,4 NQ-BC for 24 h, with 10 μM necrostatin-1 for 24 h, and with 2.5 μM phorbol 12-myristate 13-acetate (PMA) for 3 h. Our experiment revealed that under normal physiological conditions, when macrophages receive external stimuli (such as pathogens; in this experiment, PMA), they will form METs and capture and kill pathogens, thus exerting innate immune function. However, exposure to 1,4 NQ-BC can cause necroptosis in macrophages, accompanied by increased levels of reactive oxygen species (ROS) and cytosolic calcium ions, as well as the expression disorder of inflammatory factors and chemokines, prevent the formation of METs, lead to loss of the function of capturing and killing pathogens, and weaken the innate immune function. Notably, inhibition of necroptosis restored the formation of METs, indicating that necroptosis inhibited the formation of METs. Our study was the first to explore the crosstalk mechanism between necroptosis and METs. This experiment will enrich the mechanism of macrophage injury caused by 1,4 NQ-BC exposure.

Cannabidiol Alleviates Perfluorooctanesulfonic Acid-Induced Cardiomyocyte Apoptosis by Maintaining Mitochondrial Dynamic Balance and Energy Metabolic Homeostasis

Perfluorooctanesulfonic acid (PFOS), a fluorine-containing organic compound, can be widely detected in the environment and living organisms. Accumulating evidence has shown that PFOS breaks through different biological barriers resulting in cardiac toxicity, but the underlying molecular mechanisms remain unclear. Cannabidiol (CBD) is a nonpsychoactive cannabinoid without potential adverse cardiotoxicity and has antioxidant and anti-inflammatory properties that reduce multiorgan damage and dysfunction. For these reasons, the aim of this study was to research how PFOS caused heart injury and whether CBD could attenuate PFOS-induced heart injury. Mice were fed PFOS (5 mg/kg) and/or CBD (10 mg/kg) in vivo. In vitro, H9C2 cells were intervened with PFOS (200 μM) and/or CBD (10 μM). After PFOS exposure, oxidative stress levels and the mRNA and protein expression of apoptosis-related markers increased distinctly, accompanied by mitochondrial dynamic imbalance and energy metabolism disorders in mouse heart and H9C2 cells. Moreover, terminal deoxynucleotidyl transferase dUTP nick end labeling staining, acridine orange/ethidium bromide staining and Hoechst 33258 staining signaled that the number of apoptotic cells increased after exposure to PFOS. Noteworthy, CBD simultaneous treatment alleviated a series of damages caused by PFOS-mediated oxidative stress. Our results demonstrated that CBD could alleviate PFOS-induced mitochondrial dynamics imbalance and energy metabolism disorder causing cardiomyocyte apoptosis by improving the antioxidant capacity, suggesting that CBD may represent a novel cardioprotective strategy against PFOS-induced cardiotoxicity. Our findings facilitate the understanding of the cardiotoxic effects of PFOS and the important role of CBD in protecting cardiac health.

DBP induced autophagy and necrotic apoptosis in HepG2 cells via the mitochondrial damage pathway

Phthalate esters (PAEs) are widely present in human tissues and pose significant health risks. In this study, HepG2 cells were treated with 0.0625, 0.125, 0.25, 0.5 and 1 mM Dibutyl phthalate (DBP) for 48 h to investigate mitochondrial toxicity. The results showed that DBP caused mitochondrial damage, autophagy, apoptosis and necroptosis; Transcriptomics analysis identified that MAPK and PI3K were significant factors in the cytotoxic changes induced by DBP; N-Acetyl-L-cysteine (NAC), SIRT1 activator, ERK inhibitor, p38 inhibitor and ERK siRNA treatments counteracted the changes of SIRT1/PGC-1α and Nrf2 pathway-related proteins, autophagy and necroptotic apoptosis proteins induced by DBP. While PI3K and Nrf2 inhibitors exacerbated the changes in SIRT1/PGC-1α, Nrf2-associated proteins and autophagy and necroptosis proteins induced by DBP. In addition, the autophagy inhibitor 3-MA alleviated the increase in DBP-induced necroptosis proteins. These results suggested that DBP-induced oxidative stress activated the MAPK pathway, inhibited the PI3K pathway, which in turn inhibited the SIRT1/PGC-1α pathway and Nrf2 pathway, thereby causing cell autophagy and necroptosis.

Nano-selenium protects grass carp hepatocytes against 4-tert-butylphenol-induced mitochondrial apoptosis and necroptosis via suppressing ROS-PARP1 axis

4-tert-butylphenol (4-tBP) is a monomer widely used in the synthesis of industrial chemicals, and posed a high risk to aquatic animals. Our study focused on toxic phenotype and mechanism of detoxification in grass carp hepatocytes (L8824) after 4-tBP-treatment. In this experiment, L8824 displayed hallmark phenotypes of apoptosis and necroptosis after 4-tBP exposure, as evidenced by changes in cell morphology, increased rates of apoptosis and necrosis, the loss of MMP, the accumulation of ROS, and changes in associated factors (PARP1, JNK, Bid, Bcl-2, Bax, AIFM1, CytC, Caspase 9, APAF1, Caspase 3, TNF-α, TNFR1, RIPK1, RIPK3, and MLKL). Furthermore, we found that 4-tBP-induced apoptosis and necroptosis were reversed by pretreating with N-Acetylcysteine (a ROS scavenger) and 3-Aminobenzamide (a PARP1 inhibitor), indicating that 4-tBP induced the onset of mitochondrial apoptosis and necroptosis in L8824 via activating ROS-PARP1 axis. Nano-selenium (Nano-Se) is a novel form of Se with a noteworthy antioxidant capacity. Here, Nano-Se was found to have preventive, therapeutic, and resistance effects on 4-tBP-induced L8824 apoptosis and necroptosis. Nano-Se co-treatment with 4-tBP was an optimal way to alleviate 4-tBP-induced apoptosis and necroptosis. We demonstrated for the first time that Nano-Se protected L8824 against 4-tBP-induced mitochondrial apoptosis and necroptosis through ROS-PARP1 pathway. This study will provide a new theoretical basis for 4-tBP toxicology researches and aquatic animal protection.

Tannin alleviates glyphosate exposure-induced apoptosis, necrosis and immune dysfunction in hepatic L8824 cell line by inhibiting ROS/PTEN/PI3K/AKT pathway

Glyphosate can cause tissue damage such as liver and kidney in mammals. Tannin has anti-inflammatory, antibacterial and anti-inflammatory properties. However, the effect of glyphosate on the growth of L8824 cell line and the effect of tannin on antagonism of glyphosate through the ROS/PTEN/PI3K/AKT axis are unclear. In this study, L8824 cells were treated with glyphosate (50 μg/mL) and/or tannin (4.5 μM) for 24 h to establish a model. The results showed that glyphosate exposure increased ROS and MDA levels, decreased CAT and SOD activities. PTEN was activated and the PI3K/AKT signaling pathway was inhibited. The P53/Bcl-2/Bax/CytC/Caspase3 and RIPK1/RIPK3/MLKL pathways were also activated. In addition, the cytokines and antimicrobial peptides LEAP-2, TNF-α and IL-1β were increased while β-defensin, Hepcidin, IL-2 and IFN-γ were decreased. The use of tannin reduced the adverse effects of glyphosate exposure on L8824 cells significantly. In conclusion, tannin can trigger oxidative stress via PTEN/PI3K/AKT pathway to cause apoptosis, necroptosis and immune dysfunction of L8824 cells.

Induction of autophagy via the ROS-dependent AMPK/mTOR pathway protects deoxynivalenol exposure grass carp hepatocytes damage

Deoxynivalenol (DON) is one of the most frequently found mycotoxin sources in feed and raw food products, endangering human and animal health. The mechanism of grass carp (Ctenopharyngodon idellus) liver cell (L8824) toxicity induced by DON is still unknown. The DON was administered to the L8824 cells in concentrations of 150, 200, and 250 ng/mL for 24 h. The results of this study suggested that DON could enable L8824 cells to significantly increase the levels of autophagy. Concurrently, DON could trigger autophagy through the AMPK-mTOR pathway, which upregulated the expression of p-AMPK and p-ULK1 while downregulating the expression of p-mTOR. In the meantime, DON treatment could alter the levels of expression of the related proteins in autophagy. Additionally, DON treatment dramatically reduced the activity of the antioxidant enzymes as well as increased the levels of oxidase, which increased the production of ROS in L8824 cells. This indicates that DON could induce oxidative stress. Furthermore, we discovered that DON exposure caused apoptosis, which is characterized by elevated levels of BAX, Caspase 9, Caspase 3, and decreased Bcl-2 levels. Next, it was investigated how oxidative stress affected DON-induced autophagy. The research revealed that the oxidative stress inhibitor (NAC) attenuated DON-induced autophagy. Additionally, the study also investigated how autophagy worked under the L8824 cells induced by DON. The ROS production, however, was enhanced by the addition of the autophagy inhibitor (3-MA). Additionally, co-treatment with the apoptosis inhibitor Z-VAD-FMK had no influence on autophagy. The combined findings showed that induction of autophagy via the ROS-dependent AMPK-mTOR pathway protects DON-induced L8824 cells from damage.

Selenium alleviates cadmium-induced oxidative stress, endoplasmic reticulum stress and programmed necrosis in chicken testes

Cadmium (Cd) is a common heavy metal pollutant, and one of the important target organs of its toxicity is the testis. Selenium (Se) has the ability to antagonize the toxicity of Cd. However, the mechanism of the alleviating effects of Se on Cd in chicken testis injury through oxidative stress, endoplasmic reticulum stress (ERS), and programmed necrosis remained unclear. To explore this, 80 7-day-old chickens were divided into the Control group, the Se group (1.00 mg/kg Se), the Cd group (150.00 mg/kg Cd), and the CdSe group. On the 30th and 60th days, serum and chicken testis tissue samples were collected for testing. The results showed that Cd exposure resulted in swelling and deformation of seminiferous tubules, and thinning of the seminiferous epithelium. The ROS and MDA increased, and the SOD, CAT, GSH, GSH-Px decreased. The expression of GRP78, PERK, IRE1, ATF6, CHOP, and JNK in the Cd group increased. The expression of TNF-α, TNFR1, RIP1, RIP3, MLKL, and PARP1 increased, while the expression of Caspase-8 decreased. Histopathological changes, oxidative stress, ERS, and programmed necrosis were improved after CdSe treatment. In conclusion, Se antagonized the toxicity of Cd, and Se could alleviate Cd-induced oxidative stress, ERS, and programmed necrosis in chicken testis.

EGCG alleviated Mn exposure-caused carp kidney damage via trpm2-NLRP3-TNF-α-JNK pathway: Oxidative stress, inflammation, and tight junction dysfunction

Manganese (Mn), an essential trace metal element in organisms. However, with extensive use of Mn in industry and agriculture, Mn becomes a heavy metal pollutant in water. (-)-epigallocatechin gallate (EGCG), an tea polyphenols, can alleviate metal toxicity. Kidney is an important detoxifying organ, but toxic mechanism of Mn to kidneys is unclear, which needs further research. Carp is an Asian important economical species for fisheries and a biological model for studying environmental toxicology. Thus, we established excess Mn and EGCG-supplemented carp model to explore molecular mechanism of EGCG alleviating Mn-caused carp kidney damage. In this experiment, we set a control group (the Con group), a Mn treatment group (the Mn group, 90 mg/L Mn), a EGCG supplement group (the EG group, 75 mg/kg EGCG), and a combined group (the Mn + EG group, 90 mg/L Mn and 75 mg/kg EGCG). Transcriptome, qRT-PCR, kit, and morphology method results indicated that excess Mn caused oxidative stress, inflammatory damage, and tight junction dysfunction in carp kidneys. Excess Mn-triggered oxidative stress caused tight junction dysfunction via trpm2-NLRP3-TNF-α-JNK pathway and inflammation. EGCG reversed the harm of Mn to fish through the above mechanism. The findings of this study provided the evidence of EGCG-alleviated Mn poisoning and offered new ideas for reducing heavy metal environmental pollution risk.

Combined negative effects of microplastics and plasticizer DEHP: The increased release of Nets delays wound healing in mice

Environmental harmful pollutants microplastics (MPs) and di (2-ethyl) hexyl phthalate (DEHP) are widely residual in the environment, which may cause lesion to multiple apparatus by inducing oxidative stress, threatening the health of human and animals. Neutrophil extracellular traps (Nets) are involved in skin wound healing. Most studies focused on the individual effects of different poisons on animals and ecosystems, but there are few studies on the accumulation and interaction of multiple poisons. The purpose of this study is to explore the effect of DEHP and MPs co-exposure on skin wound healing and the formation of Nets. For this purpose, we detected this hypothesis by replicating the DEHP and MPs-exposed skin wound model in mice, as well as the co-culture system of neutrophil and fibroblast. The results displayed that MPs and DEHP exposure delayed skin healing, which was more pronounced in the combined exposure group. In vitro and in vivo experiments confirmed that compared with the DEHP or MPs group, the DEHP+MPs group had more significant oxidative stress, increased Nets release and inflammatory factors, and inhibited the Wnt/β-catenin pathway and fibrosis-related factors. N-acetylcysteine (NAC) attenuated these phenomena. Through the co-culture system, we confirmed that the overproduction of Nets induced fibroblasts to exacerbate inflammatory responses and inhibit Wnt pathway and fibrosis. Overall, DEHP and MPs can produce synergistic toxic injury in mice skin wounds, and the excessive activation of ROS/Nets can aggravate inflammatory and inhibit fibrosis, resulting in delayed wound healing.

The mitigation mechanism of hesperidin on deoxynivalenol toxicity in grass carp hepatocytes via decreasing ROS accumulation and inhibiting JNK phosphorylation

Deoxynivalenol (DON), a crucial kind of mycotoxin, is found globally present in the contaminated cereal crops including wheat, barley, maize and rice. Hesperidin (HDN) is a flavonoid with a variety of biological activities found in high concentrations in citrus fruits. However, the potential protective effects of HDN on cell damage under DON toxicity, and the role of oxidative stress, inflammation, autophagy and apoptosis in it, remain unclear. Therefore, we treated grass carp (Ctenopharyngodon idellus) liver cells (L8824 cell) with DON and HDN for 24 h. The results showed that DON exposure caused a higher ROS accumulation, activated inflammation, autophagy and apoptosis, induced the expression of cytokines (NF-kappaB, TNF-α, IL-1β, IL-6), triggered BCL2/BAX-mediated apoptosis and LC3B/P62-dependent autophagy in the L8824 cell line. Moreover, HDN reduced DON exposure-induced inflammation and autophagy by decreasing ROS accumulation and reduced DON exposure-induced apoptosis by inhibiting JNK phosphorylation. These results partly explained the mechanism of biological threat on fish under DON exposure and the potential application value of HDN in aquaculture.

β-Cyclodextrin/Azobenzene Microspheres Loaded with Paraquat Are Safe and Effective

Although paraquat is a widely used herbicide, it is toxic to humans if ingested or absorbed through an open wound. To improve the safety of paraquat, a new formulation of paraquat based on photoresponsive polymers was exploited. Photoresponsive β-cyclodextrin polymer microspheres (AZO-CD) were synthesized via a host-guest interaction between β-cyclodextrin and azobenzene. AZO-CD were characterized by Fourier transform infrared spectrometry, circular dichroism, ultraviolet (UV) spectrophotometry, and thermogravimetric analysis, and their photoresponsiveness was also evaluated. AZO-CD were used to load paraquat, which yielded photoresponsive paraquat-loaded microspheres. For the paraquat-loaded microspheres, irradiation with UV light or sunlight induced the isomerization of azobenzene into the cis form. Then, the cis-azobenzene was liberated from the cavities of the β-cyclodextrin. The paraquat-loaded microspheres released paraquat continuously over time. Furthermore, under UV light, the herbicidal capacity of the paraquat-loaded microspheres against barnyard grass was comparable to that of free paraquat at the same dose. Our findings show that loading paraquat into AZO-CD provides a safe and environmentally friendly herbicide formulation.

Crosstalk of oxidative stress, inflammation, apoptosis, and autophagy under reactive oxygen stress involved in difenoconazole-induced kidney damage in carp

Difenoconazole is a commonly used triazole fungicide in agricultural production. Because of its slow degradation and easy accumulation in the environment, it seriously endangers both animal health and the ecological environment. Therefore, it is hoped that the effects on carp kidneys can be studied by simulating difenoconazole residues in the environment. The experiment was designed with two doses (0.488 mg/L, 1.953 mg/L) as exposure concentrations of difenoconazole for 4 d. Histopathological results showed that difenoconazole could cause severe damage to the kidney structure and extensive inflammatory cell infiltration in carp. Elevated levels of Creatinine, and BUN suggested the development of kidney damage. The DHE fluorescence probe's result suggested that difenoconazole might cause reactive oxygen species (ROS) to accumulate in the kidney of carp. Difenoconazole was found to increase MDA levels while decreasing the activities of CAT, SOD, and GSH-PX, according to biochemical indicators. In addition, difenoconazole could up-regulate the transcription levels of inflammatory factors tnf-α, il-6, il-1β, and inos. At the same time, it inhibited the transcription level of il-10 and tgf-β1. The TUNEL test clearly showed that difenoconazole induced apoptosis in the kidney and vastly raised the transcript levels of apoptosis-related genes p53, caspase9, caspase3, and bax while inhibiting the expression of Bcl-2, fas, capsase8. Additionally, TEM imaging showed that clearly autophagic lysosomes and autophagosomes were formed. Elevated levels of LC3II protein expression, increased transcript levels of the autophagy-related gene atg5 as well as decreased transcript levels of p62 represented the generation of autophagy. In conclusion, the study illustrated that oxidative stress, inflammation, apoptosis, and autophagy all played roles in difenoconazole-induced kidney injury in carp, which was closely linked to ROS production. This work provides a valuable reference for studying the toxicity of difenoconazole to aquatic organisms.

Selenium mitigates the inhibitory effect of TBBPA on NETs release by regulating ROS/MAPK pathways-induced carp neutrophil apoptosis and necroptosis

Tetrabromobisphenol A (TBBPA) is one of the most common and persistent organic pollutants found in the environment. When TBBPA is ingested by organisms through various pathways and stored in the body, it shows obvious harmful effects. Selenium (Se) works as an antioxidant in the body, allowing it to withstand the poisonous effects of dangerous substances. The effects and mechanisms of Se and TBBPA on carp neutrophil immune function, apoptosis, and necroptosis, however, are unknown. As a result, we created TBBPA exposure and Se antagonism models using carp neutrophils as study objects, and we investigated the expression of genes implicated in extracellular traps (NETs), cytokines, apoptosis, and necroptosis. The findings demonstrated that extracellular traps neutrophils in the TBBPA group displayed the inhibition of NETs, apoptosis, and necrosis, as well as an increase in Reactive oxygen species (ROS) levels and activation of the MAPK pathway. The expression of genes related to the mitochondrial apoptosis pathway (Bax, Cyt-c, Bcl-2 and Caspase-3) and necroptosis pathway (MLKL, RIPK1, RIPK3, Caspase-8 and FADD) were activated. The expression of inflammatory factors IL-1 and TNF-α were increased, and the expression of IL-2 and IFN-γ were decreased. But an appropriate concentration of Se can mitigate the effects of TBBPA. Our results suggest that Se can mitigate the inhibitory effect of TBBPA on NETs release by regulating apoptosis and necroptosis of carp neutrophil via ROS/MAPK pathways. These results provide a basis information for exploring the toxicity of TBBPA, and enrich the anti-toxicity mechanism of trace element Se in the body.

Trimethyltin induces apoptosis and necroptosis of mouse liver by oxidative stress through YAP phosphorylation

Trimethyltin (TMT) is widely used as a major component of plastic stabilizers in agriculture and industry, and can accumulate in large quantities in the liver. To investigate the relationship between liver tissue damage induced by TMT exposure and YAP phosphorylation in mice, we gave the mice drinking water containing 0.01 mg/mL TMT for 14 days to establish an in vivo experimental model, and continuously treated AML12 cells with 20 μM TMT for 24 h to establish an in vitro experimental model. Transcriptomics revealed that TMT exposure altered 62,466 apparently diversely expressed genes, including 1197 upregulated and 899 downregulated genes, and that enrichment of the Hippo pathway occurred. Moreover, western blotting (WB) and quantitative real-time PCR (qRTPCR) results showed that TMT exposure triggered an increase in the expression of P-YAP, apoptosis and necroptosis-interrelated genes, and a decrease in Bcl-2 expression in mouse livers tissues and AML12 cells. The expression of P-YAP was significantly suppressed in the TRULI-treated TMT-exposed AML12 cells, while oxidative stress levels and damage were also significantly attenuated. In conclusion, TMT triggers YAP phosphorylation to induce oxidative stress inducing apoptosis and necroptosis in mouse livers tissues. Our results confirm the liver toxic effect and specific mechanism of TMT.

Melatonin ameliorates imidacloprid-induced intestinal injury by negatively regulating the PGN/P38MAPK pathway in the common carp (Cyprinuscarpio)

Imidacloprid (IMI), one of the most frequently used neonicotinoid insecticides in agriculture, is resided in surface water worldwide and poses a threat to aquatic organisms. Melatonin (MT) provides effective protection against insecticide-induced toxicity, nevertheless, the toxic effects and whether MT attenuates intestinal injury caused by IMI exposure in the common carps remains poorly explored. Previous studies have reported adverse effects of IMI exposure on intestinal health status. Therefore, we first demonstrated that IMI altered the composition and function of the intestinal microbiota, destroying the integrity of intestinal ultrastructure, increasing intestinal permeability. Meanwhile, metagenomic sequencing and ELISA kits results hypothesized that peptidoglycan (PGN) is an IMI-triggered intestinal microbial metabolite. Subsequently, we thus further elucidated that IMI induced an increase in intestinal tight junction permeability by inducing PGN secretion in vitro model. MT addition dramatically attenuated IMI-induced intestinal toxicity by remitting PGN synthesis and thus resecuring tight junction permeability, thereby reducing intestinal injury. SB203580 was supplied as a P38MAPK inhibitor to alleviate the increased permeability of tight junctions induced by IMI/PGN. Therefore, these findings confirmed that MT protects against IMI-induced intestinal injury by negatively regulating PGN/P38MAPK pathway to antagonize the increased tight junction permeability.

Tannic acid antagonizes atrazine exposure-induced autophagy and DNA damage crosstalk in grass carp hepatocytes via NO/iNOS/NF-κB signaling pathway to maintain stable immune function

Atrazine (ATR) is a herbicide widely used in grass crops. The pollution of the soil and water environment is extremely harmful to aquatic animals and their offspring. iNOS/NO upregulation, DNA damage and cellular autophagy affect the immune function of fish liver cells. The effects of ATR at exposure doses on grass carp hepatocytes in terms of autophagy and DNA damage effects in genotoxicity, as well as the antagonistic effects of TAN on the above phenotypes and the internal mechanisms are not known. Therefore, we constructed control (Con group), ATR exposure (ATR group), TAN exposure (TAN group) and mixed group (ATR + TAN group) models on grass carp hepatocytes. Validation was performed by comet assay, MDC staining, qRT-PCR and protein blotting assay as well as iNOS/NO indicator levels and expression of immune factors as these experimental methods. Our data indicate that iNOS/NO assay kit measured that ATR treatment resulted in a significant increase in iNOS/NO activity and levels in grass carp hepatocytes (p < 0.05). We also found that NO/iNOS/NF-κB pathway genes were significantly activated (p < 0.05) at the exposure dose of ATR (3 μg mL-1). In addition, the proportion of cells that died due to DNA damage, autophagy, and immunotoxic effects was significantly increased at the exposure dose of ATR. Comet assay protein blotting detected increased DNA damage in cells at the ATR exposure dose (p < 0.05). MDC staining and qRT-PCR and protein blotting to detect the proportion of autophagic cells and autophagy-related genes also appeared upregulated at the exposed dose of ATR (p < 0.05). In brief, this study showed that ATR exposure caused cellular DNA damage and autophagy via the NO/iNOS/NF-κB axis, which led to immunotoxic effects and eventual death of grass carp hepatocytes. The present study facilitates the demonstration of the molecular mechanism of TAN alleviation of ATR cytotoxicity from the perspective of NO-mediated iNOS/NF-κB axis. It provides insights into the protection of farmed fish from agricultural contaminants and opens up new horizons in the use of natural plant-derived monomers for the clinical treatment of antagonistic triazine pesticide poisoning.

Eucalyptol relieves the toxicity of diisobutyl phthalate in Ctenopharyngodon idellus kidney cells through Keap1/Nrf2/HO-1 pathway: Apoptosis-autophagy crosstalk and immunoregulation

Diisobutyl phthalate (DiBP), one of the commonly used plasticizers in industry, is an endocrine disruptor and environmental contaminant that can persist in water and threaten the health of aquatic creatures. Eucalyptol (Euc), a monoterpenoid extracted from plants, has been proved to have anti-inflammatory, antioxidant, and detoxification properties. However, the protective mechanism of Euc against cell injury caused by DiBP exposure and the involvement of apoptosis, autophagy, and immunity remains unknown. In the current investigation, 27.8 μg/mL DiBP or/and 20 μM Euc has been applied to Ctenopharyngodon idellus kidney (CIK) cells for 24 h. The findings showed that exposure to DiBP raised intracellular ROS levels, inducing oxidative stress, and enhanced the rate of apoptosis as well as the expression of the apoptotic markers Bax, Caspase3, Caspase9, and Cytc while decreasing the expression of Bcl-2. Furthermore, DiBP inhibited IL-2, IFN-γ, Hepcidin-1, and β-defensin expression and elevated TNF-α, and IL-1β levels, causing immune dysfunction. DiBP and Euc co-treatment significantly activated the Keap1/Nrf2/HO-1 pathway, restored antioxidant enzyme activity, and elevated autophagy pathway-associated genes ATG5, Beclin1, and LC3B decreased p62 expression, enhanced cell autophagy, reduced apoptosis, and improved immunity. In conclusion, Euc promotes autophagy, alleviates DiBP-induced apoptosis, and improves immunological dysfunction in CIK cells by regulating the Keap1/Nrf2/HO-1 pathway. These results demonstrated the threat of DiBP exposure to fish while providing a theoretical foundation for using Euc in aquaculture.